If you kept a european car after warranty expires, you can run into thousands of repair cost each year.
If you kept a japanese car after warranty expires, you probably will face a lot less, but there's still regular oil changes and the usual maintenance issues that will be a hundred and ramp up to hundreds if you keep them too long after warranty.
There's no doubt that the Teslas new or used are a little more expensive to get it, but the maintenance costs are ok.
My family has driven Ford Windstar, Honda Civic, Accord, Insight (hybrid) Lexus RX300, Infiniti QX50, QX60, mercedes C, E, S. The Honda hybrid was the cheapest to maintain, the civic and accord are only slightly more. The Lexus and Infinitis are more expensive but still not a big deal.
The Ford Windstar was a nightmare - it had some sort of problem with plastic parts in the engine that caused severe leaks when it was a year old and it eventually died when it was 6 years old. It was junked. Although most repairs were under warranty, I never bought another american car after that.
The Mercedes were great when new, after 6 years or so, the problems start coming up and they were extremely expensive to fix. Especially the Model S, twice on 2 models. The thing about the Benz model S is that the air suspension is so smooth and interiors so luxurious that you get addicted to it. I thought the first one was just a fluke, so I replaced it with a newer model. Like clockwork, 7the year, major issues crop up, from air suspension components (hideously expensive) to transmission and miscelaneous electronics and parts.
The thing with mercedes is that many components that are due to fail are placed in awkward places that require many hours of labor to get to - parts had to be disassembled and removed before you can replace them --- they never gave a thought about time to replace in their design. Today, if someone must buy a benz, I would definitely say get rid of it before the warranty runs out and eat the massive depreciation --- $5000 annual repair costs are not uncommon for the model S.
The Tesla is still under warranty, but we know about the major cost factors --- MCU (eMMC problem), the door handles, charger mechanism, there's not much else - meaning if I replace them before the warranty runs out keeping the car longer may be acceptable. Besides, used Teslas seem to retain more of their value, making trading in less expensive than the european models.